Premium
Crystallization behavior of glucomannan
Author(s) -
Chanzy H. D.,
Grosrenaud A.,
Joseleau J. P.,
Dubé M.,
Marchessault R. H.
Publication year - 1982
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.360210206
Subject(s) - glucomannan , mannan , crystallization , chemistry , crystallography , cellulose , mannose , chemical engineering , whiskers , whisker , polysaccharide , materials science , biochemistry , organic chemistry , composite material , engineering
Five different glucomannan samples were recrystallized from dilute solution. Depending on the experimental conditions, the crystals obtained could be identified as corresponding to the mannan I (anhydrous precipitate of more or less regular lozenge‐shaped crystals) or mannan II (hydrated gel‐forming pseudo‐fibrillar precipitate). High‐molecular‐weight material, low temperature of crystallization, or a polar crystallization medium favored the mannan II polymorph, whereas a low‐molecular weight, a high temperature of crystallization, and a crystallization medium of low polarity yielded the mannan I polymorph. Since the base‐plane unit‐cell dimensions are fairly constant with respect to variation of glucose, it is likely that isomorphous replacement of mannose by glucose occurs in glucomannan crystallization; the data also indicate that perfection of the glucomannan crystals was reduced in specimens having a high glucose:mannose ratio. The oriented crystallization of glucomannan on cellulose microfibrils was also studied under conditions where the mannan I polymorph was obtained. This gave shish‐kebab structures that were characterized.